1. Field of the Invention
The present invention concerns a structural cryogenic tank wall having an outer skin and an inner skin between which there is a cavity containing a thermally insulative structure.
The invention also concerns a cryogenic tank including a wall of the above kind and equipping terrestrial, maritime or aerospace vehicles necessitating the storage of cryogenic fuels, for example reusable space launch vehicles.
The invention also concerns a method of manufacturing a wall of the above kind and a method of diagnosing faults to which such walls are susceptible.
2. Description of the Prior Art
Reusable space launch vehicles are a promising way to reduce launch costs. Building a launcher of this kind entails solving technical problems such as minimizing the structural mass of the launch vehicle and continuously monitoring the structural integrity of the tanks. To reduce the mass of the launch vehicle it is advantageous for the wall of a cryogenic tank to assure the tank, structure and functional surveillance functions simultaneously.
Most prior art methods for monitoring the functional integrity of the wall of a cryogenic tank are not of a global nature in that they assume that the fault will occur at a particular location where a sensor is installed. Apart from the fact that such methods are complex and incomplete, repairing the tank generally entails total demounting of the faulty structure.
The aim of the invention is to provide a cryogenic tank wall which has a structural function and a tank functional integrity monitoring function.
Another aim of the invention is to facilitate locating and replacing faulty parts of the wall to avoid replacing the entire cryogenic tank.
Another aim of the invention is to prevent atmospheric cryo-pumping.